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RE: New Giant GP Super Sportster!!!!!

That's what I was thinking. I have an electric version of the SS, and it has a nice hatch just forward of the canopy. There is
lots of room to do the same thing on the GSS. Oh, I have a Stearman gear too!!!

RE: New Giant GP Super Sportster!!!!!

Well I broke a aileron pushrod this weekend. Fortunately it did not cause too many issues and Iwas able to land with no problem. I know the pushrods are week but I think it was my fault. Inever cleaned the flux off of the link after Ifinished soldering it and it rusted. I looked at the others and there are at least 3 in the same state. As we all know Flux is acidic so I am sure that is the reason. The thread side is perfect on all of them, it is only the side that was soldered. I know all of you are using Carbon Fiber rods but Ihave this $100 Tower Hobbies GCburning a hole in my wallet so Iwas wondering if there was any acceptable alternatives from them that any of you can recommend. I also shot a video with the contour GPS but was not happy with the outcome. I need to make some changes and try again but my mount works great so at least that part of the project was a success

RE: New Giant GP Super Sportster!!!!!

Glad to hear your plane is okay.

I'm actually using fiberglass arrow shafts for my pushrods. The 1/4" maple dowel rod fits in them and I make plugs about 1" long to hold the 4-40threaded rod.Just drill and tap the dowel and screw in the rod. I use bolts to prevent theplugs from coming loose. Afterwatching the video on howmuch the pushrodsvibrate, I don't trust glue alone for the plugs.

RE: New Giant GP Super Sportster!!!!!

It really was not too big of a deal. I noticed that the plane was not very responsive and I had to move the aileron trim over to the left quite a bit to get it to fly true. I rocked the wings from side to side and noticed it was not moving like it should. Other then that it flew pretty normal. We had a very heavy headwind so that made landing slow nice and easy. Arrow shafts are a great idea. Do you have any photos of the individual pieces, I do not understand what you are securing with bolts

RE: New Giant GP Super Sportster!!!!!

I don't have pictures of the individual pieces, but if you look at the pictures in my gallery, you should be able to figure out how the bolts work. I have tried both nylon and hardwood inserts and they both work well.

RE: New Giant GP Super Sportster!!!!!

Ok that looks good, I completely understand now after looking at your pics. Have you looked at the Dave Brown pushrod system? http://www3.towerhobbies.com/cgi-bin...&I=LXB901&P=ML. How do the dimensions of your arrows compare to these:
Inside diameter: 6.4mm (.250")
Outside diameter: 7.54mm (.297")
Length: 914.4mm (36")

Also, what kind of Rod ends do you recommend? I am tired of the sloppy fittings I have now. I have already replaced the servo arms more then once as the holes start to enlarge and the slop in the control surfaces increases. I want to fix this for good now.

RE: New Giant GP Super Sportster!!!!!

Dubro makes a really heavy nylon clevis with locking pins. They're great because unlike a ball link they support the control horn or servo arm on both sides so there's no twisting forces imposed? Those pins can get frustrating, so often I'll toss those and use screws w/locknuts. Otherwise, I generally go with ball links.

Some have used carbon fiber tube for pushrods, and if necessary to stiffen further, adding a layer of shrink wrap....

RE: New Giant GP Super Sportster!!!!!

I use the heavy duty ball links and found that they do wear out so they should be inspected occasionally. Mine lasted about 2,000 flights before I had to replace them. The one on the rudder wore out first, it was pretty loose for a long time before I replaced it.

RE: New Giant GP Super Sportster!!!!!

I just ordered the Dave Brown Fiberglass pushrod kit along with the Dubro heavy duty ball links and some 4-40 threaded rod. I also decided to get a LiFe Rx battery. I will put that in the GSSand Iwill take the 6V NiMh pack in there now and use that to upgrade the decade old NiCd pack in my Jupiter. Now the Jupiter moves to the front of the pack as Iwill be flying her this week while the GSSis in for upgrades. Thanks guys for the input, I really appreciate it.- MD

RE: New Giant GP Super Sportster!!!!!

The ID of the arrow shafts work out great for the use of hardwood dowels. Not sure why Dave's kit only has 5 inserts with it. The odd number is a pain for making control rods, it should come with an even number. Come to think of it,I think the fifth one is for a dual pushrod setup. Anyway more inserts are usually required.

RE: New Giant GP Super Sportster!!!!!

Steve:
I purchased 3 more of the end kits to go with it. I also like your idea of the 1/4" dowel and Imay use that instead as these pushrods have the same i.d. I figured I would get all options to my hangar and then will make the final call when Iput it all together.

RE: New Giant GP Super Sportster!!!!!

Sounds good. I couldn't get the extra end kits locally and didn't want to wait, so I used the dowel since I had that on hand. The end kits are easier to use. You need to follow Jim'sadvice and make sure you clean them and rough up the surfacea littleso the glue sticks well.

RE: New Giant GP Super Sportster!!!!!

There was a guy posting about doing that earlier, but haven't heard much from him since. I'm flying mine with the Syssa 30, also rear exhaust. I think the DLE35 would be a great combo with the rear exhaust and a little extra kick provided by a few extra cc's?

The Syssa likes to rev up to make power, struggles with a 19" prop. Running mine on an APC 18x6w because of that. It's OK, but that 35 swings a 19" easily, might do a good job with a 20"? The extra power provided by the bigger prop sizes would be a good thing! It's something the Sportster could use to good advantage. -Al

RE: New Giant GP Super Sportster!!!!!

Had an "event" during the third flight today. Flight #37 since the re-cover and new engine was installed. When I switched on my receiver and did my battery checks, the #2 battery was weak and sluggish.

Turns out it had a bad cell, went to about .3 volts in about 15 min after a full charge during my off-plane testing.

RE: New Giant GP Super Sportster!!!!!

It's greater yet to have awareness of the fact stuff like that happens, so you can keep an eye out for it? Good to hear you caught it!

This time of year we don't get to fly much, so my Sportster's going down for some much needed attention. Converting the twin battery power system (including a 10 year old set of sub-C nicads that still cycle just fine!) over to single A123, and installing the new Syssa muffler that I've been putting off for a while now.

I'll be doing some work on the tail, trying to get some weight out of that. The big batteries that are being removed are right up by the firewall, and weigh several times what the A123 will, so I'm concerned over a CoG shift to the rear if I don't do something to conteract that. I've got solid flying wires (4/40!) that will be replaced with lightweight SS cables, and some really heavy control rods I'm going to replace with carbon fiber. Hoping that gets me close....

The old girl has treated me well. Makes me look like I know what I'm doing on occasion, so it's time to pay some attention to her! Will see if that doesn't extend her life a couple more seasons.
-Al

RE: New Giant GP Super Sportster!!!!!

I received all of my pushrod materials and am in the process of machining some aluminum ends. I thought the plastic end kit from dave brown was a little less then what i wanted and I feel I can do better. I have the first 2 done now so at least the development part is complete. Now only 8 more to go.Once complete I will post pics and details in case any one is interested. I have the ends down to 1.5 grams each so weight is well within reason and strength will not be a factor. When I ordered the pushrod materials I also ordered a LiFe Battery from Lifesource. I realize these are not identical to A123 but the chemistry is pretty close from what I can tell. I like the fact that they come with several connectors including a balance lead and boy is it light.My Jupiter needed a new battery so I took the 6.0v NiMh out of the sportster for that and will put in the new LiFe battery. I don't know if it's thespeed from the higher voltage or if I am just doing it correctly but that plane snaps so fast now I can barely followit. Been having fun with the Jupiter but I can't wait to get my GSS back in the air. Hopefully I can get back to the lathe this weekend to complete the pushrod project

RE: New Giant GP Super Sportster!!!!!

Well my pushrod project has been an adventure and some might say a lot of wasted time. The aluminum ends that I was machining simply did not work. I should have just made them from standard aluminum stock that I had. Rather I used Solid aluminum rivets that were almost in the shape I needed but the alloy used for rivets is not good for machining and frankly I was not sure the threads would be strong enough. I broke more mini drill bits and taps then I care to admit. After giving up I switched to plan b and that was to use the complete Dave Brown system with plastic ends. I made some changes to the way they install but nothing significant. The reason for this post is to bring up the old CG debate again. My pushrods are lighter then the originals but when you add the ball links and hardware each pushrod is about 6 grams heavier then the original setup. This means that I will be adding 18 grams to the tail or over a half ounce. I know the CGneeded to be pushed back as I had it very conservative but I know a few of you have said it can go way back. Just wanted to know what everyone is running for CG so Ican have an idea of what works and what is dangerous.

RE: New Giant GP Super Sportster!!!!!

I've not been very shy of telling anyone I prefer a rear CG, but I'm not going to say the dimension I use will be of benefit to anyone else? In fact, the dimension I use would likely crash a few planes. It's back far enough where if improperly managed it will allow the plane to literally stop mid air. When it slows, you may need to hold the nose down a bit to continue a glide? It's pretty extreme.

The point is, the CG is something you can/need to play with. Changes are not that sensitive on this airframe. You can start moving it back in 1/4" increments until it starts acting like what I'm talking about above. I wouldn't go much beyond that.

Highly recommend doing you low speed testing with these changes 3 mistakes high. You don't want to learn about these handling changes on short final?

I believe the reward for this screwing around will put a grin on the face of anyone demanding more from the plane than going up and doing laps with it... -Al

RE: New Giant GP Super Sportster!!!!!

Your pushrod project may not be in vain. I think the starting point for the CG, as listed in the manual,is way too far forward. The manual lists the CG as 5-1/4", + or - 1".

My CG is set at 6-1/4" back from the leading edge of the wing.

When I roll inverted, the plane will nose down slightly and will require one or two clicks of down to maintain level flight. I think if I went back another 1/4" or so, it would be perfect. I already have my batteries as far back as I can comfortably mount them and I refuse to add lead to a plane.

I use flaperons for landing to slow the plane down and give a good glideslope.

RE: New Giant GP Super Sportster!!!!!

I ended up with about 5 1/2 from LE and the difference was amazing. After some modifications to the LG and front firewall several months earlier I never re balanced it so it was probably quite nose heavy. the pushrods turned out to be just the amount of weight it needed. The new LiFe RX pack went into the exact same spot as the original batt and there is still no lead in the plane! The plane feels much more responsive. I pulled 45 upline and rolled inverted, it required no stick to hold it. Level inverted flight requires half the amount of elevator as before. Landing into a headwind required throttle as the plane slowed down significantly on approach. Bounced the first landing but the last were super smoothe with half the normal ground roll.

Pushrod project turned out fantastic. I ended up using Dave Brown plastic ends for the shafts. The metal ends I was machining did not work out as anticipated so moved to plan B. Should have made that plan A from the start but now I know. Thes pushrods are so stiff and there is zero play in any of the linkages. Putting Ball links at both ends of the rods definitely adds weight but in the end it was just the right amount and I could not be happier with the results. I think it was Al who said he does not like putting ball links on the end of servos becaus of the side load on the arm. I had another problem in that the nuts to secure the 4-40 bolt to the servo arm would not clear the servo. After a lot of research I found some Dubro double servo arms designed for ball links so ordered them up (at $10 per pair). Got them home and found out they were way to big. Turns out I needed the hole in closer then the innermost hole already there and if you drilled it then the ball link will have clearance issues. Fortunately the material they make those arms out of is super strong and the bottom is built up to allow clearance for the nut. the material machines like metal so I turned them on my lathe to remove the top part of the double arm and it came out perfect. I probably machined $3 of material off of a $5 part but in the end they fit perfectly and even though not double supported anymore, I am sure plenty strong.

Have any of you been automatically unsubscribed to this thread? I was wondering why no one replied as that is not the norm so I went to the page while surfing and found your replies.

RE: New Giant GP Super Sportster!!!!!

I have had that happen on most of the threads I subscribe to on RCU. For some reason I have stopped getting notices on just about all my threads. As you I have found I have to go looking for them and re-subscribe even though it shows I am subscribed. Then I get them again for a while. I find I am spending less an less time on RCU because of it.

RE: New Giant GP Super Sportster!!!!!

Muttdog,

I never heard of anyone being "unsubscribed" to a thread. With the software they use here anything is possible. I'm still trying to figure out how they can have text in threads that is "invisible" to the RCU search engine, but "visible" to Google searches.

I flew my GS this morning, it was cold, cold and cold; my eyes watered a lot with the North winds, it was still worth it. This may be my last flight for this year since the weather forcast is not good. The plane flew great, with the cool weather it has unlimited vertical.

My plane slows so much on landing that I can do tailwheel first landings with no problem. I really like to use the flaperons when there is no wind.